The prior art heat tube or heat plate serves as heat transfer element in phase change operation. Since the heat tube 12 is formed by an inner plate 112 and a mask plate 113. The mask plate 113 is two flat plates for clamping from two sides or is placed in a round tube. All these are formed as a basic structure.
Since it is required that the heat tube is operated in a closed body, four corners of a heat plate or two ends of a heat tube must be sealed. Currently, as shown in FIGS. 1 and 2, a punching method is used. A pair of upper and lower molding plates 8 and 9 serve to press the edges 111 of the heat tube or heat plate, as shown in FIG. 1. Even it is pressed with a wave-like shape, and then one side thereof is cut.
The newly generated rim has a good tightness. However, this can not be retained for a long period of time. Therefore, the rim of a heat tube or heat plate must pass through a tin furnace 7 for being adhered with tin material at the rim portion. Thus, the rim is substantially sealed.
However, this prior art way has many defects. Since the rim portion is very thin, only a thin layer of tin is adhered to the rim potion, the fluid therewith in is easy to drain out.
Since pressing the opening for cut away is a temporary sealing, the operation of adding with tin must be performed very rapidly. Sometimes, a cooling device is necessary for dissipating the residual heat from the tin furnace to prevent that the heat tube is damaged. Otherwise, not only the sealing effect is not complete, but also the high temperature of the tin furnace will cause that high temperature and high pressure are formed in the heat tube so as to induce an explosion of the heat tube.
Furthermore, the edge generated from pressing the rim is very thin so that two ends become more acute and the tin adhered to the opening is thin. In the assembling process of the product, workers are possible to be harmed or the heat tube is damaged due to a collision. Moreover, the thin edge is easily deformed. Maybe, in the secondary finishing, such as plating or polishing, it is easy to be damaged due to the thin tin layer.
Therefore, the prior art heat tube or heat plate is necessary to be improved in the process of manufacturing.
Alternatively, as shown in FIG. 3, another machining way is illustrated. As the upper view shown in FIG. 3A, since punching process will induce some acute protrusions 21 at two ends of the heat tube 2. A pair of clamping elements 3 and 5 serves to clamp and fix the heat tube, while another pair of molds 5 and 6 serves to press the heat tube inversely to be formed with tip tapers at two ends, as shown in the lateral view of FIG. 3B, for reducing the width thereof. This way is beneficial to the present invention.